For the most part, yes, you should always include the pins in your fluorescent tube measurements but this can vary depending on how the manufacturer lists them so it is worth taking down the measurements with and without the pins to be sure. 

Manufacturer packaging will often include the length without the pins but to make sure it fits within your fitting we highly recommend taking down the measurement with the pins and many websites that sell the goods will advise the measurements with the pins to be sure it goes into the appropriate fitting.  This is because the consumer may have disposed of the original packaging and a part number may not be visible on the tube itself due to some years or more passing since the tube was replaced.  

The Importance of an Accurate Measurement

Fluorescent tubes come in standardized diameters which are indicated by the T numbers (such as T5, T8, T12).  They often come in standardized lengths as well which will be indicated in feet or millimetres.  The measurement given for the length however can be an approximation, it will never be out by more than a few millimetres but this is why it is important to take the measurements both with and without the pins.  If the measurement is incorrect this means the tube will not fit.  It may even sit in the fitting but if it is too short it will not make proper connection with the lamp-holders within the fittings meaning they will likely flicker or not light up at all.

The Two Crucial Measurements

Below is a guide on how to measure the tube with and without the pins:

1. Overall Length (Tip-to-Tip, Including Pins)

For this one you will need to include the pins for this measurement.

The overall length is the total distance from the very tip of one pin on one end of the tube to the tip of the pin on the opposite end.  We would recommend using a tape measure to do this and to measure from the end point of one pin to the one on the opposite end.

2. Glass Tube Length (End Cap to End Cap, Excluding Pins)

This secondary measurement will help to confirm the tube is the correct one if both this measurement and the measurement with the pins matches.  It should also help as a reference point if the manufacturer of the tube has chosen to list the measurement without the pins rather than with. To take this measurement you should measure the glass tube from the end cap on the tube beginning on one side to the end cap on the other side.

Pin Structures and Compatibility

Not all fluorescent tube pins are the same, this will mostly be designated by the T number on the fitting; it will be listed in the part number if it is a U-Bend or circular tube.

Practical Measurement Checklist

If you follow these steps below this will help you to ensure you are purchasing the correct length and diameter of tube:

1. Safety First: Turn off the power to the fixture before removing the old tube.
2. Remove the Old Tube: Gently twist the tube 90 degrees and slide it out.
3. Measure Overall Length: Lay the tube flat and measure from the tip of the pins on  the end to the tip of the pin on the opposite end. Record this measurement as precisely as you can. 
4. Identify Diameter and Base: Make a note of the diameter (this can be identified by the T number - such as T8 or T5) and check to make a note of the pin type (usually two pins).
5. Check Markings (If Available): Look for a manufacturer part number or other markings that indicate the wattage (W) and color temperature (Kelvin or K).  This would show as F32T8/841/ECO for example.
6. Measure the Fixture: Measure the distance between the two end caps on the tube to give you the length of the tube without the pins.